A method for image analysis was implemented to determine the edge pixels of two biopolymer-based thermoplastic filaments during their hot melt isothermal sintering at 120 °C. Successive inverted ellipses are adjusted to the contour of the sintered filaments and lead to the identification of the parameters of the corresponding lemniscates of Booth. The different steps of the morphological image analysis are detailed, from 8-bit coded acquired images (1 frame/s), to the final fitting of the optimized mathematical functions describing the evolution of the filaments envelope.
View Article and Find Full Text PDFStarch-legume protein composites were obtained by extrusion of pea flour and pea starch-protein blend at various specific mechanical energies (100-2000 kJ/kg) and a temperature low enough to avoid expansion. The morphology of these composites displayed protein aggregates dispersed in a starch matrix, revealed by microscopy. Image analysis was used to determine the median width of protein aggregates (D), their total perimeter and surface, from which a protein/starch interface index (I) was derived.
View Article and Find Full Text PDFThis study combines experimental and numerical approaches to investigate the microstructure and mechanical behaviour of non-miscible plasticised starch/zein blends. The concept of Representative Elementary Size (RES) is used to rank the effect of five different plasticisers (cholinium acetate, glycerol, butyl methyl imidazolium chloride, glycerol-choline chloride, urea-choline chloride) inducing microstructural and mechanical changes in the blends. Microstructural and mechanical RESs are derived from microscopy image analysis and Finite Element Modelling of elasticity behaviour of studied blends.
View Article and Find Full Text PDFX-ray tomography is a relevant technique for the dynamic follow-up of gas bubbles in an opaque viscoelastic matrix, especially using image analysis. It has been applied here to pieces of fermenting wheat flour dough of various compositions, at two different voxel sizes (15 and 5 μm). The resulting evolution of the main cellular features shows that the creation of cellular structures follows two regimes that are defined by a characteristic time of connectivity, tc [30 and 80 min]: first (t ≤ tc), bubbles grow freely and then (t ≥ tc) they become connected since the percolation of the gas phase is limited by liquid films.
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